Method and system for setting up a bearer

ABSTRACT

Method and system for setting up a bearer are disclosed. The bearer setup method includes these steps: a packet data network gateway (PGW) obtains first quality of service (QoS) information and a first bearer identifier (ID), and sets up a bearer between the PGW and a radio access network (RAN) according to the first QoS information, where the bearer is associated with the first bearer ID; the RAN sets up a radio bearer (RB) with a user equipment (UE) according to second QoS information associated with the first QoS information, where the RB is associated with a second bearer ID associated with the first bearer ID.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 12/757,638,filed on Apr. 9, 2010, which is a continuation of InternationalApplication No. PCT/CN2008/072614, filed on Oct. 8, 2008. TheInternational Application claims priority to Chinese Patent ApplicationNo. 200710163715.9, filed on Oct. 11, 2007. All of the above-referencedapplications are hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to the field of communicationtechnologies, and in particular, to a method and system for setting up abearer.

BACKGROUND OF THE INVENTION

The Third Generation Partnership Project (3GPP) proposes a long termevolution/system architecture evolution (LTE/SAE) network. The purposeof the LTE network is to reduce delay, to increase user data rate, toimprove system capacity, and to lower coverage costs. For betterdescription, the SAE network architecture is divided into the followingtwo parts, as shown in FIG. 1.

The first part includes a user equipment (UE) 101, a radio accessnetwork (RAN) 102, a serving general packet radio service support node(SGSN) 103, and a packet data network gateway (PGW) 104.

The RAN consists of a radio network controller (RNC) and a NodeB. TheRNC is adapted to allocate and control radio resources of the NodeBconnected to or related to the RNC. The RNC implements functions such asconnection setup and disconnection, handover, macro diversity combining(MDC), and radio resource management control. The NodeB converts datastreams and manages a part of radio resources.

The SGSN is responsible for forwarding input/output Internet Protocol(IP) packets for UEs in a local service area. The SGSN providesfunctions such as routing and forwarding of packets in the local servicearea, provision of services for all the UEs in the local service area,encryption and authentication, session management, and mobilitymanagement. The SGSN 103 is an SGSN of 3GPP R7 or earlier versions. TheSGSN 103 is designed to enable the SAE architecture to be compatiblewith earlier systems.

The PGW is responsible for connecting a UE to a user plane anchor pointof a packet data network (PDN) and communicating with external PDNs. Itis also responsible for routing and forwarding packets, enhancing policycharging, filtering packets based on each user. In addition, the PGW isconnected to an operator's IP network.

The second part includes a UE 101, an RAN 105, an SGSN 106, a servinggateway (SGW) 107, and a PGW 104.

The SGW stores user plane contexts of the UE, for example, IP addressand routing information of the UE, and performs lawful interception andpacket data routing.

The SGSN 106 is an SGSN of 3GPP R8, and can communicate with the SGWdirectly.

A method for setting up a bearer in the prior art is based on an SGSN of3GPP R7 or earlier versions, which can be connected to the PGW directly.Thus, a bearer between the UE and the PGW can set up through the RAN andthe SGSN.

SUMMARY OF THE INVENTION

The embodiments of the present invention provide a method and system forsetting up a bearer. Based on the embodiments of the present invention,a complete bearer setup solution can be accomplished based on 3GPP R8.

A method for setting up a bearer according to an embodiment of thepresent invention includes:

-   -   obtaining, by a packet data network gateway (PGW), first quality        of service (QoS) information and a first bearer identifier (ID),        and setting up a bearer between the PGW and a radio access        network (RAN) according to the first QoS information, where the        bearer is associated with the first bearer ID; and    -   setting up, by the RAN, a radio bearer (RB) between the RAN and        a user equipment (UE) according to second QoS information, where        the RB is associated with a second bearer ID, the second QoS        information is associated with the first QoS information, and        the second bearer ID is associated with the first bearer ID.

A packet data network gateway (PGW) according to an embodiment of thepresent invention includes:

-   -   a QoS information obtaining unit, adapted to obtain first QoS        information;    -   an uplink bearer resource (UBR) allocating unit, adapted to        allocate information about the first UBR for a first bearer        according to the first QoS information;    -   an information sending unit, adapted to send the first QoS        information and information about the first UBR;    -   an information receiving unit, adapted to receive the first QoS        information, first downlink bearer resource (DBR) information,        and a first bearer ID; and    -   an information storing unit, adapted to store the first QoS        information, the information about the first DBR, and the first        bearer ID.

A serving gateway (SGW) according to an embodiment of the presentinvention includes:

-   -   a QoS information obtaining unit, adapted to obtain first QoS        information;    -   a DBR allocating unit, adapted to allocate a first DBR for a        first bearer according to the first QoS information;    -   a DBR information sending unit, adapted to send the first QoS        information and information about the first DBR;    -   a UBR information receiving unit, adapted to receive the first        QoS information, information about the first UBR, and a first        bearer ID;    -   a UBR information storing unit, adapted to store the first QoS        information, the information about the first UBR, and the first        bearer ID;    -   a UBR allocating unit, adapted to allocate a second UBR for a        second bearer according to the first QoS information;    -   a UBR information sending unit, adapted to send the first QoS        information and information about the second UBR;    -   a DBR information receiving unit, adapted to receive the first        QoS information, information about the second DBR, and the first        bearer ID; and    -   a DBR information storing unit, adapted to store the first QoS        information, the information about the second DBR, and the first        bearer ID.

A serving general packet radio service support node (SGSN) according toan embodiment of the present invention includes:

-   -   a QoS information obtaining unit, adapted to obtain first QoS        information;    -   a DBR allocating unit, adapted to allocate a second DBR for a        second bearer according to the first QoS information;    -   a DBR information sending unit, adapted to send the first QoS        information and information about the second DBR;    -   a UBR information receiving unit, adapted to receive the first        QoS information, information about the second UBR, and a first        bearer ID;    -   a UBR information storing unit, adapted to store the first QoS        information, the information about the second UBR, and the first        bearer ID;    -   a UBR allocating unit, adapted to allocate a third UBR for the        second bearer according to second QoS information associated        with the first QoS information;    -   a UBR information sending unit, adapted to send the second QoS        information and information about the third UBR;    -   a DBR information receiving unit, adapted to receive the second        QoS information, the information about the third DBR, and a        second bearer ID associated with the first bearer ID; and    -   a DBR information storing unit, adapted to store the second QoS        information, the information about the third DBR, and the second        bearer ID.

A UE according to an embodiment of the present invention includes:

-   -   a QoS information obtaining unit, adapted to obtain second QoS        information;    -   a DBR allocating unit, adapted to allocate a radio bearer DBR        for the RB according to the second QoS information;    -   an information sending unit, adapted to send the second QoS        information and information about the radio bearer DBR;    -   an information receiving unit, adapted to receive the second QoS        information, radio bearer UBR information, and a second bearer        ID; and    -   an information storing unit, adapted to store the second QoS        information, radio bearer UBR information, and the second bearer        ID.

It can be seen from the above description that, by using the technicalsolution according to embodiments of the present invention, a completebearer setup solution can be realized based on 3GPP R8 and the resourcesof each network element can also be utilized adequately.

BRIEF DESCRIPTION OF THE DRAWINGS

For better understanding of the technical solution according to theembodiments of the present invention or in the prior art, the followingdescribes the accompanying drawings that are used in the embodiments ofthe present invention or in the prior art. Obviously, the followingdrawings are some exemplary embodiments of the present invention only.Those skilled in the art may obtain other drawings based on thefollowing drawings without creative work.

FIG. 1 shows an architecture of an SAE network in the prior art;

FIG. 2 is a flowchart of a method for setting up a bearer in the priorart;

FIG. 3 is a flowchart of a method for setting up a bearer according to afirst embodiment of the present invention;

FIG. 4 is a flowchart of a method for setting up a bearer according to asecond embodiment of the present invention;

FIG. 5 is a flowchart of a method for setting up a bearer according to athird embodiment of the present invention;

FIG. 6 is a flowchart of a method for setting up a bearer according to afourth embodiment of the present invention;

FIG. 7 is a flowchart of a method for setting up a bearer according to afifth embodiment of the present invention;

FIG. 8 is a flowchart of a method for setting up a bearer according to asixth embodiment of the present invention;

FIG. 9 is a flowchart of a method for setting up a bearer according to aseventh embodiment of the present invention;

FIG. 10 is a flowchart of a method for setting up a bearer according toan eighth embodiment of the present invention;

FIG. 11 is a flowchart of a method for setting up a bearer according toa ninth embodiment of the present invention;

FIG. 12 is a flowchart of a method for setting up a bearer according toa tenth embodiment of the present invention;

FIG. 13 is a flowchart of a method for setting up a bearer according toan eleventh embodiment of the present invention;

FIG. 14 is a flowchart of a method for setting up a bearer according toa twelfth embodiment of the present invention;

FIG. 15 is a flowchart of a method for setting up a bearer according toa thirteenth embodiment of the present invention;

FIG. 16 is a flowchart of a method for setting up a bearer according toa fourteenth embodiment of the present invention;

FIG. 17 is a flowchart of a method for setting up a bearer according toa fifteenth embodiment of the present invention;

FIG. 18 shows a structure of a PGW according to an embodiment of thepresent invention;

FIG. 19 shows a structure of an SGW according to an embodiment of thepresent invention;

FIG. 20 shows a structure of an SGSN according to an embodiment of thepresent invention; and

FIG. 21 shows a structure of a UE according to an embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

The technical solution of the embodiments of the present invention ishereinafter described in detail with reference to the accompanyingdrawings. It is evident that the embodiments are only exemplaryembodiments of the present invention and the present invention is notlimited to such embodiments. Other embodiments that those skilled in theart obtain based on embodiments of the present invention withoutcreative work also fall in the scope of protection of the presentinvention.

FIG. 2 shows a conventional process of setting up a bearer between a UEand a PGW in which the SGSN is of 3GPP R7 or earlier versions. However,the SGSN of 3GPP R8 is connected to the PGW through the SGW so that thebearer setup solution in the prior art is not applicable to the SGSN of3GPP R8. As a result, even if an SGSN of 3GPP R8 is available in the SAEsystem, it is impossible to set up a bearer between the UE and the PGWthrough such SGSN in the method shown in FIG. 2. Thus, the resources ofnetwork entities on the network cannot be fully utilized.

The following is based on an SGSN of 3GPP R8.

FIG. 3 shows a method for setting up a bearer according to the firstembodiment of the present invention. The method includes the followingsteps:

Step 301: The PGW obtains the first QoS information and a first bearerID, and sets up a bearer between the RAN and the PGW according to thefirst QoS information, where the bearer is associated with the firstbearer ID.

The PGW may set up a bearer between the PGW and the RAN directly orforward data between the PGW and the RAN through the SGW and/or SGSNwhen setting up the bearer between the PGW and the RAN. Specifically,the following cases may exist: (1) The PGW sets up a first bearerbetween the PGW and the SGW, and the SGW sets up a bearer between theSGW and the RAN. In this case, the SGSN forwards the data between theSGW and the RAN only; (2) The PGW sets up a bearer between the PGW andthe SGSN, and the SGSN sets up a third bearer between the SGSN and theRAN. In this case, the SGW forwards the data between the PGW and theSGSN only; (3) The PGW sets up a bearer between the PGW and the UE. Inthis case, the SGW and the SGSN forward the data between the PGW and theUE; (4) The PGW sets up a first bearer between the PGW and the SGW, theSGW sets up a second bearer between the SGW and the SGSN, and the SGSNsets up a third bearer between the SGSN and the RAN.

Step 302: The RAN sets up an RB with the UE according to the second QoSinformation, where: the RB is associated with the second bearer ID; thesecond QoS information is associated with the first QoS information; andthe second bearer ID is associated with the first bearer ID.

In practical applications, the UE and the PGW may use different QoSinformation. Thus, it is required to store the mapping relationshipbetween the QoS information used by the UE and the QoS information usedby the PGW in the SGSN, SGW or RAN, so that the UE and the PGW canidentify related QoS information by mapping the QoS information duringthe data transmission. Alternatively, the UE or PGW may also storerelated mapping relationship in the UE or PGW. Similarly, the UE and thePGW may use different bearer IDs. Thus, it is required to store themapping relationship between the bearer ID used by the UE and the bearerID used by the PGW in the SGSN, SGW, or RAN, so that the UE and the PGWcan identify related bearer IDs by mapping the bearer IDs during thedata transmission. Alternatively, the UE or PGW may also store relatedmapping relationship in the UE or PGW.

The first embodiment is described supposing the SGSN stores relatedmapping relationship. The processes of storing the mapping relationshipby other network entities such as the SGW are similar to the process ofstoring the mapping relationship by the SGSN, and will not be furtherdescribed in the specification. Step 302 may also be executed beforestep 301, and step 302 and step 301 may also be executed at the sametime.

FIG. 4 shows a method for setting up a bearer according to the secondembodiment of the present invention. The method includes the followingsteps:

Step 401: The PGW sends a first message to the SGW to trigger the SGW toobtain first QoS information and a first bearer ID.

The PGW may send the first message actively to the SGW; for example, thePGW may be triggered by its own policy to send the first message. ThePGW may also send the first message passively to the SGW; for example,the PGW may be triggered by a trigger message from other networkentities that initiate bearer setup or triggered by a second messagefrom the SGW, MME or SGSN to send the first message. Similarly, the SGWmay send the second message in an active or passive manner; for example,the SGW may be triggered by a third message from the SGSN to send thesecond message. The SGSN may also send the third message in an active orpassive manner; for example, the SGSN may be triggered by a fourthmessage from the UE to send the third message.

If the first message includes the first QoS information, the SGW mayobtain the first QoS information from the first message directly. If thefirst QoS information is stored in the SGW, the SGW may obtain the firstQoS information from the SGW directly. If the first QoS information isstored in other network entities, the SGW may obtain the first QoSinformation from the network entities that store the first QoSinformation by exchanging messages.

The process of obtaining the first bearer ID is similar to that ofobtaining the first QoS information. The first QoS information and thefirst bearer ID may be obtained from different network entities or bydifferent means.

Step 402: The SGW sets up a first bearer between the SGW and the PGWaccording to the first QoS information, where the first bearer isassociated with the first bearer ID.

The following describes the process of setting up the first bearerbetween the SGW and the PGW by the SGW according to the first QoSinformation.

The SGW allocates a first DBR for the first bearer according to thefirst QoS information, and sends the first QoS information, the firstbearer ID and information about the first DBR to the PGW; the PGW storesthe information about the first DBR. If the PGW has already allocatedthe first UBR according to the first QoS information and sent theinformation about the first UBR to the SGW for storing, the setup of thefirst bearer ends. If the PGW has not allocate the first UBR accordingto the first QoS information, the PGW allocates the first UBR accordingto the first QoS information, and sends the first QoS information, thefirst bearer ID and information about the first UBR to the SGW; the SGWstores the information about the first UBR; then, the setup of the firstbearer ends.

The allocated DBR or UBR may be user plane resources. After the beareris set up, the user plane data may be transmitted through the allocatedUBR and DBR.

Step 403: The SGW sets up a second bearer between the SGW and the SGSNaccording to the first QoS information, where the second bearer isassociated with the first bearer ID.

The following describes the process of setting up the second bearerbetween the SGW and the SGSN by the SGW according to the first QoSinformation.

The SGW allocates a second UBR for the second bearer, and sends thefirst QoS information, the first bearer ID and information about thesecond UBR to the SGSN.

The SGSN stores the information about the second UBR. If the SGSN hasalready allocated a second DBR according to the first QoS informationand sent the information about the second DBR to the SGW for storing,the setup of the second bearer ends.

If the SGSN has not allocated a second DBR according to the first QoSinformation, the SGSN allocates a second DBR according to the first QoSinformation, and sends the first QoS information, the first bearer IDand information about the second DBR to the SGW; the SGW stores theinformation about the second DBR; then, the setup of the second bearerends.

Step 404: The SGSN sets up a third bearer between the SGSN and the RANaccording to the second QoS information associated with the first QoSinformation, where the third bearer is associated with the second bearerID.

Step 405: The RAN sets up an RB with the UE according to the second QoSinformation, where the RB is associated with the second bearer ID whichis associated with the first bearer ID.

Because the second bearer ID is obtained by mapping the first bearer ID,the first bearer ID is associated with the second bearer ID on aone-to-one basis. Thus, the bearer is associated with the second bearerID as well as with the first bearer ID. Similarly, the first QoSinformation is associated with the second QoS information. In fact, thefirst QoS information and the second QoS information are the same andonly the expression forms are different.

The preceding bearers may be set up in a random sequence. The precedingembodiment describes only one case. In practical applications, thebearers may be set up in any sequence or at the same time.

The process of setting up the third bearer between the SGSN and the RANby the SGSN according to the second QoS information associated with thefirst QoS information is as follows: The SGSN allocates a third UBR forthe third bearer according to the second QoS information, and sends thesecond QoS information, second bearer ID associated with the firstbearer ID and information about the third UBR to the RAN; the RAN storesthe information about the third UBR, allocates a third DBR according tothe second QoS information, and sends the information about the thirdDBR to the SGSN; the SGSN stores the information about the third DBR;then the setup of the third bearer ends. During the setup of the thirdbearer, the RAN may set up an RB with the UE according to the second QoSinformation, where the RB is associated with the second bearer ID whichis associated with the first bearer ID.

If the RAN and the SGW use the same type of QoS information and bearerIDs, the first QoS information and the second QoS information are thesame and so are the first bearer ID and the second bearer ID. If the RANand the SGW use different versions of QoS information, the mappingrelationship between the QoS information needs to be stored in the SGSN.Thus, the first QoS information used in the SGW may be mapped into thesecond QoS information used in the RAN according to such mappingrelationship. For example, the QoS information of R8 used in the SGW ismapped into the QoS information of R7 used in the RAN. Similarly, if theRAN and the SGW use different bearer IDs, the mapping relationshipbetween the bearer IDs needs to be stored in the SGSN. Thus, the firstbearer ID used in the SGW may be mapped into the second bearer ID usedin the RAN according to such mapping relationship. For example, thebearer ID used in the SGW is mapped into a network layer service accesspoint identifier (NSAPI) used in the RAN.

In practical applications, the RAN may set up an RB with the UE throughthe following process: The RAN sends the second QoS information andsecond bearer ID to the UE; the UE allocates a first radio bearer DBRaccording to the QoS information, and sends the QoS information based onwhich the first radio bearer DBR is allocated, second bearer ID, andinformation about the first radio bearer DBR to the RAN; the RAN storesthe information about the first radio bearer DBR, allocates a firstradio bearer UBR according to the QoS information based on which thefirst radio bearer DBR is allocated, and sends such QoS information,second bearer ID, and the information about the first radio bearer UBRto the UE; and the UE stores the information about the first radiobearer UBR; then the RB is set up.

Because resources that the UE can allocate are unknown to the network,the UE may not allocate resources required by the second QoS, eventhough the second QoS information is sent to the UE. After receiving thesecond QoS information, the UE needs to judge whether the first radiobearer DBR can be allocated for the RB according to the second QoSinformation. If the first radio bearer DBR can be allocated for the RBaccording to the second QoS information, the UE sets up an RB accordingto the second QoS information; otherwise the UE needs to determine thirdQoS information according to its own resources, and sets up an RBaccording to the third QoS information.

When the UE sets up an RB by using the third QoS information, the SGWneeds to set up a second bearer and a first bearer according to fourthQoS information associated with the third QoS information. If the secondbearer and the first bearer are already set up, the SGW needs to re-setup a second bearer and a first bearer according to the fourth QoSinformation. That is, the SGW needs to update the second bearer and thefirst bearer, so that the second bearer and the first bearer can meetthe requirement of the fourth QoS information.

It can be know from the process described above that, according toembodiments of the present invention, the SGSN of 3GPP R8 may bedirectly connected to the SGW. A bearer between the UE and the PGW maybe set up through communications between the SGW and the PGW, so thatresources of each network entity can be fully utilized.

In practical applications, multiple bearers may be set up between a sameUE and a same PGW. In this case, transmitted data streams may becorrelated with a bearer through an ID which is associated with thebearer. Practically, if a traffic flow template (TFT) is used, theprocess is as follows:

The PGW may allocate an uplink TFT associated with the bearer, and sendsthe uplink TFT to the UE during the bearer setup process. Similarly, theUE may allocate a downlink TFT, and sends the downlink TFT to the PGWduring the bearer setup process.

It can be known from the preceding description that, the setup of abearer between the UE and the PGW may be triggered by any network entityin the network, for example, the PGW, UE, SGW, or PGW. The followingdescribes the preceding cases:

1. Bearer Setup Triggered by the PGW

FIG. 5 shows a method for setting up a bearer according to the thirdembodiment of the present invention. This method concerns bearer setuptriggered by the PGW. Bearer setup may be triggered through some triggermessages, for example, trigger messages from downstream nodes such asthe SGW, SGSN, RAN, and UE, trigger messages from other system relatednodes such as the MME, trigger messages from upstream nodes such as apolicy and charging rules function (PCRF), or bearer setup may betriggered by the PGW. The process includes the following steps:

Step 501: The PGW sends a bearer setup request to the SGW.

After obtaining the first QoS information from the PGW or other networknodes, the PGW allocates a first UBR for the first bearer between thePGW and the SGW according to the first QoS information, and sends abearer setup request to the SGW, where the bearer setup request mayinclude information about the first UBR, the first QoS information and afirst bearer ID, or further include uplink TFT information.

Step 502: The SGW sends a bearer setup request to the SGSN.

After receiving the bearer setup request from the PGW, the SGW storesrequired information, such as information about the first UBR, the firstQoS information and the first bearer ID.

The SGW allocates a second UBR for the second bearer between the SGW andthe SGSN according to the first QoS information, and sends a bearersetup request to the SGSN, where the bearer setup request may includeinformation about the second UBR, the first QoS information and thefirst bearer ID, or further include uplink TFT information if the SGWhas already obtained an uplink TFT.

Step 503: The SGSN sends a packet data protocol (PDP) context activationrequest to the UE.

The SGSN sends a PDP context activation request to the UE, where therequest may include QoS information, uplink TFT information and a bearerID. In the SGSN, the mapping between QoS information and mapping betweenbearer IDs may be performed. If such mapping is performed, the QoSinformation included in the PDP context activation request is the secondQoS information mapped from the first QoS information, and the bearer IDincluded in the PDP context activation request is the second bearer IDmapped from the first bearer ID. If such mapping is not performed yet,the QoS information included in the PDP context activation request isthe first QoS information, and the bearer ID included in the PDP contextactivation request is the first bearer ID.

Step 504: The UE sends a PDP context activation request to the SGSN.

After receiving the PDP context activation request, the UE may storerequired information, such as QoS information and bearer ID. If therequest includes an uplink TFT, the UE may correlate the uplink TFT withthe bearer; the UE sends a PDP context activation request carrying QoSinformation to the SGSN, where the QoS information may be the third QoSinformation re-selected by the UE or the second QoS information. If theuplink TFT is received, the request may further carry a downlink TFTassociated with the uplink TFT.

Step 505: The SGSN sends a radio access bearer (RAB) assignment requestto the RAN.

Step 506: The RAN sets up an RB with the UE.

Step 507: The RAN returns an RAB assignment response to the SGSN.

Steps 505, 506, and 507 are similar to steps 204, 205 and 206, and willnot be further described.

Step 508: The SGSN returns a bearer setup response to the SGW.

The SGSN allocates a second DBR for the second bearer according to thefirst QoS information, which may not occur in practical applications.For example, when the UE allocates downlink RB resources according tothe third QoS information rather than the second QoS informationassociated with the first QoS information, the SGSN may allocate asecond DBR according to fourth QoS information associated with the thirdQoS information; the SGSN returns a bearer setup response to the SGW,where the response may include the first QoS information, first bearerID and information about the second DBR. If the SGSN receives a downlinkTFT from the UE, the response may further include the downlink TFT.

Step 509: The SGW returns a bearer setup response to the PGW.

After receiving the bearer setup response from the SGSN, the SGW storesrelated information, such as first QoS information, first bearer ID andinformation about the second DBR, and allocates a first DBR for thefirst bearer according to the first QoS information, which may also notoccur in practical applications; the SGW returns a bearer setup responseto the PGW, where the response may include the first QoS information,first bearer ID and information about the first DBR. If the SGW receivesa downlink TFT from the SGSN, the response may further include thedownlink TFT.

Step 510: The SGSN returns a PDP context activation response to the UE.

After receiving the RAB assignment response from the RAN, the SGSN mayreturn a PDP context activation response to the UE, notifying the UEthat bearer setup is completed.

FIG. 5 describes only one of the implementation modes. In practicalapplications, the sequence of steps may be changed. For example, step508, step 510 and step 507 may be performed in any sequence or at thesame time.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the PGW through communications between the SGW and the PGW.Thus, resources of each network entity in the network are fullyutilized.

FIG. 6 shows a method for setting up a bearer according to the fourthembodiment of the present invention. This method concerns bearer setuptriggered by the PGW, and includes the following steps:

Step 601: The PGW sends a bearer setup request to the SGW.

Then, the setup of a first bearer begins.

Step 602: The SGW sends a bearer setup request to the SGSN.

Step 603: The SGSN sends a PDP context activation request to the UE.

Step 604: The UE sends a PDP context activation request to the SGSN.

Step 605: The SGSN sends a PDP context creation request to the SGW.

The setup of a second bearer begins. The SGSN allocates a second DBR forthe second bearer, and sends the information about the second DBR, firstQoS information and the first bearer ID to the SGW through the PDPcontext creation request.

Step 606: The SGW returns a bearer setup response to the PGW.

Then, the setup of the first bearer ends.

Step 607: The SGW returns a PDP context creation response to the SGSN.

After receiving the PDP context creation request, the SGW stores relatedinformation, allocates a second UBR for the second bearer, and sends theinformation about the second UBR, first QoS information and first bearerID to the SGW through the PDP context creation response; the SGW storesrelated information. Then, the setup of the second bearer ends.

Step 608: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 609: The RAN sets up an RB with the UE.

Step 610: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 611: The SGSN sends a PDP context update request to the SGW.

If the third bearer between the SGSN and the RAN uses the third QoSinformation selected by the UE, the SGSN may re-allocate a second DBRaccording to the fourth QoS information associated with the third QoSinformation, and send a PDP context update request that carries theinformation of the re-allocated second DBR, fourth QoS information, andfirst bearer ID to the SGW to trigger the SGW to re-allocate a secondUBR and update the current second bearer.

Step 612: The SGW sends a bearer update message to the PGW.

The SGW further sends a bearer update message to the PGW to update thefirst bearer.

Step 613: The SGW returns a PDP context update response to the SGSN.

The SGW stores related information, and notifies the SGSN through thePDP context update response after re-allocating the second UBR accordingto the fourth QoS information; after the SGSN stores related informationagain, the update of the second bearer ends.

Step 614: The SGSN returns a PDP context activation response to the UE.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW may betriggered through communications between the SGW and the PGW. Thus,resources of each network entity in the network are fully utilized.

FIG. 7 shows a method for setting up a bearer according to the fifthembodiment of the present invention. This method concerns bearer setuptriggered by the PGW, and includes the following steps:

Step 701: The PGW sends a bearer setup request to the SGW.

Then, the setup of a first bearer begins.

Step 702: The SGW sends a bearer setup request to the SGSN.

Then, the setup of a second bearer begins.

Step 703: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 704: The RAN sets up an RB with the UE.

Step 705: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 706: The SGSN returns a bearer setup response to the SGW.

Then, the setup of the second bearer ends.

Step 707: The SGW returns a bearer setup response to the PGW.

Then, the setup of the first bearer ends.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW may betriggered by the PGW through communications between the SGW and the PGW.Thus, resources of each network entity in the network are fullyutilized.

2. Bearer Setup Triggered by the UE

FIG. 8 shows a method for setting up a bearer according to the sixthembodiment of the present invention. This method concerns bearer setuptriggered by the UE, and includes the following steps:

Step 801: The UE sends a PDP context activation request to the SGSN.

The UE is triggered by its own policy or other network entities toinitiate bearer setup, and sends a third trigger message to the SGSN,where the third trigger message may be a PDP context activation request,which may include any of the second QoS information, second bearer IDand downlink TFT or any combination thereof or none of the precedinginformation.

Step 802: The SGSN sends a bearer setup request to the SGW.

After obtaining the first QoS information and first bearer ID, the SGSNallocates a second DBR according to the first QoS information. Then, thesetup of a second bearer begins.

Step 803: The SGW sends a bearer setup request to the PGW.

Then, the setup of a first bearer begins.

Step 804: The PGW returns a bearer setup response to the SGW.

Then, the setup of the first bearer ends.

Step 805: The SGW returns a bearer setup response to the SGSN.

Then, the setup of the second bearer ends.

Step 806: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 807: The RAN sets up an RB with the UE.

Step 808: The RAN returns an RAB assignment response to the SGSN.

Step 809: The SGSN sends a bearer update message to the SGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the second bearer needs to be updated.

Step 810: The SGW sends a bearer update message to the PGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the first bearer needs to be updated. Step 809 andstep 810 may be performed in any sequence or at the same time.

Step 811: The SGSN returns a PDP context activation response to the UE.

Then, the setup of the third bearer ends.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the UE through communications between the SGW and the PGW.Thus, resources of each network entity in the network are fullyutilized.

FIG. 9 shows a method for setting up a bearer according to the seventhembodiment of the present invention. This method concerns bearer setuptriggered by the UE, and includes the following steps:

Step 901: The UE sends a PDP context activation request to the SGSN.

The request may include any of the second QoS information, second bearerID and downlink TFT or any combination thereof or none of the precedinginformation.

Step 902: The SGSN sends a bearer setup notification to the SGW.

The notification may include any of the second QoS information, firstbearer ID and downlink TFT or any combination thereof or none of thepreceding information.

Step 903: The SGW sends a bearer setup notification to the PGW.

The notification may include any of the second QoS information, firstbearer ID and downlink TFT or any combination thereof or none of thepreceding information.

Step 904: The PGW sends a bearer setup request to the SGW.

After the PGW obtains the first QoS information and first bearer ID, thesetup of a first bearer begins.

Step 905: The SGW sends a bearer setup request to the SGSN.

Then, the setup of a second bearer begins.

Step 906: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 907: The RAN sets up an RB with the UE.

Step 908: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 909: The SGSN returns a bearer setup response to the SGW.

Then, the setup of the second bearer ends.

Step 910: The SGW returns a bearer setup response to the PGW.

Then, the setup of the first bearer ends. Step 909 and step 910 may beperformed in any sequence or at the same time.

Step 911: The SGSN returns a PDP context activation response to the UE.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the UE through communications between the SGW and the PGW.Thus, resources of each network entity in the network are fullyutilized.

FIG. 10 shows a method for setting up a bearer according to the eighthembodiment of the present invention. This method concerns bearer setuptriggered by the UE, and includes the following steps:

Step 1001: The UE sends a PDP context activation request to the SGSN.

Step 1002: The SGSN sends a bearer setup notification to the SGW.

Step 1003: The SGW sends a bearer setup request to the PGW.

After the SGW obtains the first QoS information and first bearer ID, thesetup of a first bearer begins.

Step 1004: The PGW returns a bearer setup response to the SGW.

Then, the setup of the first bearer ends.

Step 1005: The SGW sends a bearer setup request to the SGSN.

Then, the setup of a second bearer begins.

Step 1006: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 1007: The RAN sets up an RB with the UE.

Step 1008: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 1009: The SGSN sends a bearer setup response to the SGW.

Then, the setup of the second bearer ends.

Step 1010: The SGW sends a bearer update message to the PGW. Step 1009and step 1010 may be performed in any sequence or at the same time.

Step 1011: The SGSN returns a PDP context activation response to the UE.

If the third bearer and the second bearer are set up by using QoSinformation different from the first bearer, the first bearer needs tobe updated.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the UE through communications between the SGW and the PGW.Thus, resources of each network entity in the network are fullyutilized.

FIG. 11 shows a method for setting up a bearer according to the ninthembodiment of the present invention. This method concerns bearer setuptriggered by the UE, and includes the following steps:

Step 1101: The UE sends a PDP context activation request to the SGSN.

Step 1102: The SGSN sends a PDP context creation request to the SGW.

After the SGSN obtains the first QoS information and first bearer ID,the setup of a second bearer begins.

Step 1103: The SGW sends a bearer setup request to the PGW.

Then, the setup of a first bearer begins.

Step 1104: The PGW returns a bearer setup response to the SGW.

Then, the setup of the first bearer ends.

Step 1105: The SGW returns a PDP context creation response to the SGSN.

Then, the setup of the second bearer ends.

Step 1106: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 1107: The RAN sets up an RB with the UE.

Step 1108: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 1109: The SGSN sends a PDP context update request to the SGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the second bearer that is already set up needs tobe updated.

Step 1110: The SGW sends a bearer update message to the PGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the first bearer that is already set up needs tobe updated.

Step 1111: The SGW returns a PDP context update response to the SGSN.

Then, the update of the second bearer ends.

Step 1112: The SGSN returns a PDP context activation response to the UE.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the UE through communications between the SGW and the PGW.Thus, resources of each network entity in the network are fullyutilized.

FIG. 12 shows a method for setting up a bearer according to the tenthembodiment of the present invention. This method concerns bearer setuptriggered by the UE, and includes the following steps:

Step 1201: The UE sends a PDP context activation request to the SGSN.

Step 1202: The SGSN sends a PDP context creation request to the SGW.

Then, the setup of a second bearer begins.

Step 1203: The SGW sends a bearer setup notification to the PGW.

The notification may carry the first QoS information and the firstbearer ID.

Step 1204: The PGW sends a bearer setup request to the SGW.

Then, the setup of a first bearer begins.

Step 1205: The SGW returns a PDP context creation response to the SGSN.

Then, the setup of the second bearer ends.

Step 1206: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 1207: The RAN sets up an RB with the UE.

Step 1208: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 1209: The SGSN sends a PDP context update request to the SGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the second bearer that is already set up needs tobe updated.

Step 1210: The SGW sends a bearer setup response to the PGW.

The response may carry the fourth QoS information. Thus, after receivingthe response, the PGW may re-allocate a first UBR; after the SGWreceives the information of the re-allocated first UBR, the setup of thefirst bearer ends.

Step 1211: The SGW returns a PDP context update response to the SGSN.

Then, the update of the second bearer ends.

Step 1212: The SGSN returns a PDP context activation response to the UE.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the UE through communications between the SGW and the PGW.Thus, resources of each network entity in the network are fullyutilized.

3. Bearer Setup Triggered by the SGW

FIG. 13 shows a method for setting up a bearer according to the eleventhembodiment of the present invention. This method concerns bearer setuptriggered by the SGW, and includes the following steps:

Step 1301: The SGW sends a bearer setup request to the PGW.

After obtaining the first QoS information and first bearer ID, the SGWsends a first trigger message to the PGW. Then, the setup of a firstbearer begins. The first trigger message may be a bearer setup requestor a bearer setup notification. In this embodiment, the first triggermessage is a bearer setup request.

Step 1302: The PGW returns a bearer setup response to the SGW.

Then, the setup of the first bearer ends.

Step 1303: The SGW sends a bearer setup request to the SGSN.

Then, the setup of a second bearer begins.

Step 1304: The SGSN sends a PDP context activation request to the UE.

Step 1305: The UE sends a PDP context activation request to the SGSN.

Step 1306: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 1307: The RAN sets up an RB with the UE.

Step 1308: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 1309: The SGSN returns a bearer setup response to the SGW.

If the third bearer is set up by using the second QoS informationassociated with the first QoS information, the setup of the secondbearer ends. If the third bearer is set up by using the third QoSinformation determined by the UE, the response may carry fourth QoSinformation associated with the third QoS information. The SGWre-allocates a second UBR according to the fourth QoS information; afterthe SGSN updates the information of the re-allocated second UBR, thesetup of the second bearer ends.

Step 1310: The SGSN returns a PDP context activation response to the UE.

Step 1311: The SGW sends a bearer update message to the PGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the first bearer that is already set up needs tobe updated.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the SGW through communications between the SGW and the PGW.Thus, resources of each network entity in the network are fullyutilized.

FIG. 14 shows a method for setting up a bearer according to the twelfthembodiment of the present invention. This method concerns bearer setuptriggered by the SGW, and includes the following steps:

Step 1401: The SGW sends a bearer setup request to the PGW.

Then, the setup of a first bearer begins.

Step 1402: The PGW returns a bearer setup response to the SGW.

Then, the setup of the first bearer ends.

Step 1403: The SGW sends a bearer setup request to the SGSN.

Step 1404: The SGSN sends a PDP context activation request to the UE.

Step 1405: The UE sends a PDP context activation request to the SGSN.

Step 1406: The SGSN sends a PDP context creation request to the SGW.

Then, the setup of a second bearer begins.

Step 1407: The SGW returns a PDP context creation response to the SGSN.

Then, the setup of the second bearer ends.

Step 1408: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 1408: The RAN sets up an RB with the UE.

Step 1410: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 1411: The SGSN sends a PDP context update request to the SGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the second bearer that is already set up begins tobe updated.

Step 1412: The SGW sends a bearer update message to the PGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the first bearer that is already set up needs tobe updated.

Step 1413: The SGW returns a PDP context update response to the SGSN.

Then, the update of the second bearer ends.

Step 1414: The SGSN returns a PDP context activation response to the UE.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the SGW through communications between the SGW and the PGW.Thus, resources of each network entity in the network are fullyutilized.

FIG. 15 shows a method for setting up a bearer according to thethirteenth embodiment of the present invention. This method concernsbearer setup triggered by the SGW, and includes the following steps:

Step 1501: The SGW sends a bearer setup request to the PGW.

After the SGW obtains the first bearer ID and first QoS information, thesetup of a first bearer begins.

Step 1502: The PGW returns a bearer setup response to the SGW.

Then, the setup of the first bearer ends.

Step 1503: The SGW sends a bearer setup request to the SGSN.

Then, the setup of a second bearer begins.

Step 1504: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 1505: The RAN sets up an RB with the UE.

Step 1506: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 1507: The SGSN returns a bearer setup response to the SGW.

Then, the setup of the second bearer ends.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the SGW through communications between the SGW and the PGW.Thus, resources of each network entity in the network are fullyutilized.

4. Bearer Setup Triggered by the SGSN

FIG. 16 shows a method for setting up a bearer according to thefourteenth embodiment of the present invention. This method concernsbearer setup triggered by the SGSN, and includes the following steps:

Step 1601: The SGSN sends a bearer setup request to the SGW.

After obtaining the first QoS information and first bearer ID, the SGSNsends a second trigger message to the SGW. Then, the setup of a secondbearer begins. The second trigger message may be a bearer setup request,a bearer setup notification or a PDP context creation/update request. Inthis embodiment, the second trigger message is a bearer setup request.

Step 1602: The SGW sends a bearer setup request to the PGW.

Then, the setup of a first bearer begins.

Step 1603: The PGW returns a bearer setup response to the SGW.

Then, the setup of the first bearer ends.

Step 1604: The SGW returns a bearer setup response to the SGSN.

Then, the setup of the second bearer ends.

Step 1605: The SGSN sends a PDP context activation request to the UE.

Step 1606: The UE sends a PDP context activation request to the SGSN.

Step 1607: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 1608: The RAN sets up an RB with the UE.

Step 1609: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 1610: The SGSN sends a bearer update message to the SGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the second bearer that is already set up needs tobe updated.

Step 1611: The SGW sends a bearer update message to the POW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the first bearer that is already set up needs tobe updated. Step 1610 and step 1611 may be performed in any sequence orat the same time.

Step 1612: The SGSN returns a PDP context activation response to the UE.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the SGSN through communications between the SGW and thePGW. Thus, resources of each network entity in the network are fullyutilized.

FIG. 17 shows a method for setting up a bearer according to thefifteenth embodiment of the present invention. This method concernsbearer setup triggered by the SGSN, and includes the following steps:

Step 1701: The SGSN sends a bearer setup request to the SGW.

After the SGSN obtains the first QoS information and first bearer ID,the setup of a second bearer begins.

Step 1702: The SGW sends a bearer setup request to the PGW.

Then, the setup of a first bearer begins.

Step 1703: The PGW returns a bearer setup response to the SGW.

Then, the setup of the first bearer ends.

Step 1704: The SGW returns a bearer setup response to the SGSN.

Then, the setup of the second bearer ends.

Step 1705: The SGSN sends an RAB assignment request to the RAN.

Then, the setup of a third bearer begins.

Step 1706: The RAN sets up an RB with the UE.

Step 1707: The RAN returns an RAB assignment response to the SGSN.

Then, the setup of the third bearer ends.

Step 1708: The SGSN sends a bearer update message to the SGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the second bearer that is already set up needs tobe updated.

Step 1709: The SGW sends a bearer update message to the PGW.

If the third bearer is set up by using the third QoS informationdetermined by the UE, the first bearer that is already set up needs tobe updated.

In this embodiment, when the SGSN of 3GPP R8 is connected to the SGWdirectly, the setup of the bearer between the UE and the PGW istriggered by the SGSN through communications between the SGW and thePGW. Thus, resources of each network entity in the network are fullyutilized.

The preceding embodiments 1 to 15 describe the cases that the SGSNparticipates in transmission of user plane data. In practicalapplications, the SGSN may not participate in the transmission of userplane data. In this case, the SGSN does not allocate the second DBR andthird UBR, and may act as a transit node for exchanging the user planeinformation between the RAN and the SGW. That is, the SGSN may send thereceived SGW uplink user plane information to the RAN and the receivedRAN downlink user plane information to the SGW. Thus, the bearer betweenthe RAN and the SGW is directly set up.

Similarly, the SGW may also not participate in the transmission of userplane data. In this case, the SGW does not allocate the first DBR andsecond UBR, and may act as the transit node for exchanging the userplane information between the SGSN and the PGW. That is, the SGW maysend the received PGW uplink user plane information to the SGSN and thereceived SGSN downlink user plane information to the PGW. Thus, thebearer between the SGSN and the PGW is directly set up.

Of course, it is also possible that neither the SGW nor the SGSN mayparticipate in the transmission of user plane data. In this case, thebearer between the RAN and the PGW is directly set up.

FIG. 18 shows a PGW according to an embodiment of the present invention.The PGW includes:

-   -   a QoS information obtaining unit 1801, adapted to obtain first        QoS information;    -   a UBR allocating unit 1802, adapted to allocate a first UBR for        a first bearer according to the first QoS information;    -   an information sending unit 1803, adapted to send the first QoS        information and information about the first UBR;    -   an information receiving unit 1804, adapted to receive the first        QoS information, information about the first DBR and first        bearer ID; and an information storing unit 1805, adapted to        store the first QoS information, information about the first DBR        and first bearer ID.

In this embodiment of the PGW, when the SGSN of 3GPP R8 is connected tothe SGW directly, the SGSN may set up a bearer between the UE and thePGW through communications between the SGW and the PGW. Thus, resourcesof each network entity in the network are fully utilized.

In practical applications, the PGW according to this embodiment mayfurther include:

-   -   a bearer ID obtaining unit, adapted to obtain a first bearer ID;        and    -   the information sending unit 1803, further adapted to send the        first bearer ID along with the first QoS information and        information about the first UBR.

The PGW according to this embodiment may initiate bearer setup activelyor it may be triggered by the trigger information of other networkdevices to initiate bearer setup. When the PGW is triggered by othernetwork devices, the PGW according to this embodiment may furtherinclude:

-   -   a trigger information receiving unit, adapted to receive the        trigger information for triggering bearer setup; and    -   the QoS information obtaining unit 1801, adapted to obtain the        first QoS information after the trigger information receiving        unit receives the trigger information.

Because multiple bearers may be set up between the PGW and the same UE,these bearers may be set up based on different QoS information. Todifferentiate these bearers, the PGW according to this embodiment of thepresent invention may further include:

-   -   a TFT allocating unit, adapted to allocate an uplink TFT        associated with a bearer;    -   a TFT sending unit, adapted to send the uplink TFT, where: the        uplink TFT is processed by the UE; when the UE is connected to        the PGW directly, the uplink TFT may be sent to the UE directly;        when the UE is connected to the PGW through other network        devices, the uplink TFT is sent to the UE through other network        devices;    -   a TFT receiving unit, adapted to receive a downlink TFT        associated with a bearer, where the downlink TFT is processed by        the PGW; and    -   a TFT storing unit, adapted to store the downlink TFT.

FIG. 19 shows an SGW according to an embodiment of the presentinvention. The SGW includes:

-   -   a QoS information obtaining unit 1901, adapted to obtain first        QoS information;    -   a DBR allocating unit 1902, adapted to allocate a first DBR for        a first bearer according to the first QoS information;    -   a DBR information sending unit 1903, adapted to send the first        QoS information and information about the first DBR;    -   a UBR information receiving unit 1904, adapted to receive the        first QoS information, information about the first UBR and first        bearer ID;    -   a UBR information storing unit 1905, adapted to store the first        QoS information, information about the first UBR and first        bearer ID;    -   a UBR allocating unit 1906, adapted to allocate a second UBR for        the second bearer according to the first QoS information;    -   a UBR information sending unit 1907, adapted to send the first        QoS information and information about the second UBR;    -   a DBR information receiving unit 1908, adapted to receive the        first QoS information, information about the second DBR and        first bearer ID; and    -   a DBR information storing unit 1909, adapted to store the first        QoS information, information about the second DBR and first        bearer ID.

In this embodiment of the SGW, when the SGSN of 3GPP R8 is connected tothe SGW directly, the SGSN may set up a bearer between the UE and thePGW through communications between the SGW and the PGW. Thus, resourcesof each network entity in the network are fully utilized.

In practical applications, the SGW according to this embodiment mayfurther include:

-   -   a bearer ID obtaining unit, adapted to obtain a first bearer ID;    -   the DBR information sending unit 1903, further adapted to send        the first bearer ID along with the first QoS information and        information about the first DBR; and    -   the UBR information sending unit 1907, further adapted to send        the first bearer ID along with the first QoS information and        information about the second UBR.

The SGW according to this embodiment may trigger the PGW to initiatebearer setup. Thus, the SGW according to this embodiment may furtherinclude:

-   -   a trigger information sending unit, adapted to send trigger        information for triggering bearer setup.

FIG. 20 shows an SGSN according to an embodiment of the presentinvention. The SGSN includes:

-   -   a QoS information obtaining unit 2001, adapted to obtain first        QoS information;    -   a DBR allocating unit 2002, adapted to allocate a second DBR for        a second bearer according to the first QoS information;    -   a DBR information sending unit 2003, adapted to send the first        QoS information and information about the second DBR;    -   a UBR information receiving unit 2004, adapted to receive the        first QoS information, information about the second UBR, and        first bearer ID;    -   a UBR information storing unit 2005, adapted to store the first        QoS information, information about the second UBR, and first        bearer ID;    -   a UBR allocating unit 2006, adapted to allocate a third UBR for        the second bearer according to the second QoS information        associated with the first QoS information;    -   a UBR information sending unit 2007, adapted to send the second        QoS information and information about the third UBR;    -   a DBR information receiving unit 2008, adapted to receive the        second QoS information, information about the third DBR, and        second bearer ID associated with the first bearer ID; and    -   a DBR information storing unit 2009, adapted to store the second        QoS information, information about the third DBR, and second        bearer ID.

In this embodiment of the SGSN, when the SGSN of 3GPP R8 is connected tothe SGW directly, the SGSN may set up a bearer between the UE and thePGW through communications between the SGW and the POW. Thus, resourcesof each network entity in the network are fully utilized.

Because the UE and the SGW may use different QoS information, the SGSNaccording to this embodiment may further include:

-   -   a QoS mapping relationship processing unit, adapted to: store        the mapping relationship between QoS information, and map the        first QoS information into the second QoS information according        to the mapping relationship between QoS information.

In practical applications, the SGSN according to this embodiment mayfurther include:

-   -   a bearer ID obtaining unit, adapted to obtain the first bearer        ID;    -   the DBR information sending unit 2003, further adapted to send        the first bearer ID along with the first QoS information and        information about the second DBR; and    -   the UBR information sending unit 2007, further adapted to send        the second bearer ID associated with the first bearer ID along        with the second QoS information and information about the third        UBR.

Because the UE and the SGW may use different bearer IDs, the SGSNaccording to this embodiment may further include:

-   -   a bearer ID mapping relationship processing unit, adapted to:        store the mapping relationship between bearer IDs, and map the        first bearer ID into the second bearer ID according to the        mapping relationship between bearer IDs.

Because the SGSN according to this embodiment may trigger the PSW toinitiate bearer setup, the SGSN according to this embodiment may furtherinclude:

-   -   a trigger information sending unit, adapted to send trigger        information for triggering bearer setup.

FIG. 21 shows a UE according to an embodiment of the present invention.The UE includes:

-   -   a QoS information obtaining unit 2101, adapted to obtain second        QoS information;    -   a DBR allocating unit 2102, adapted to allocate a radio bearer        DBR for the RB according to the second QoS information;    -   an information sending unit 2103, adapted to send the second QoS        information and information about the radio bearer DBR;    -   an information receiving unit 2104, adapted to receive the        second QoS information, radio bearer UBR information, and second        bearer ID; and    -   an information storing unit 2105, adapted to store the second        QoS information, radio bearer UBR information, and second bearer        ID.

In this embodiment of the UE, when the SGSN of 3GPP R8 is connected tothe SGW directly, the SGSN may set up a bearer between the UE and thePGW through communications between the SGW and the PGW. Thus, resourcesof each network entity in the network are fully utilized.

In practical applications, the UE according to this embodiment mayfurther include:

-   -   a bearer ID obtaining unit, adapted to obtain the second bearer        ID; and    -   the information sending unit 2103, further adapted to send the        second bearer ID along with the second QoS information and        information about the DBR.

The UE according to this embodiment may trigger the PGW to initiatebearer setup. Thus, the UE according to this embodiment may furtherinclude:

-   -   a trigger information sending unit, adapted to send trigger        information for triggering bearer setup.

It is understandable to those skilled in the art that all or part of thesteps in the preceding embodiments may be performed by hardwarefollowing instructions of a program. The program may be stored in acomputer readable storage medium. When being executed, the programcarries out a process including the following steps:

-   -   the PGW obtains first QoS information and a first bearer ID, and        sets up a bearer between the PGW and the RAN according to the        first QoS information, where the bearer is associated with the        first bearer ID; and    -   the RAN sets up an RB with the UE according to the second QoS        information associated with the first QoS information, where the        RB is associated with the second bearer ID associated with the        first bearer ID.

The preceding storage medium may be a read-only memory (ROM), a magneticdisk or a compact disk (CD).

In the technical solution of the present invention, when the UE isconnected to the SGW through the SGSN, the SGSN and the SGW set up abearer between the UE and the PGW. Thus, resources of each networkentity in the network are fully utilized.

Detailed above are method and system for setting up a bearer accordingto embodiments of the present invention. The embodiments are intended tohelp understand the methods and key ideas of the present invention only,and not intended to limit the present invention. It is apparent thatthose skilled in the art can make various modifications and variationsto the present invention without departing from the spirit and scope ofthe present invention.

1. A method for setting up a bearer, the method comprising: setting up, by a serving general packet radio service support node (SGSN), a bearer between the SGSN and a packet data network gateway (PGW) through a serving gateway (SGW) according to first quality of service (QoS) information, wherein the bearer between the SGSN and the PGW is associated with a first bearer ID; and setting up, by the SGSN, a bearer between the SGSN and a radio access network (RAN) according to second QoS information which is mapped from the first QoS information according to a mapping relationship between the first Qos information and the second QoS information, wherein the bearer between the SGSN and the RAN is associated with a second bearer ID which is mapped from the first bearer ID according to a mapping relationship between the first bearer ID and the second bearer ID; wherein the setting up, by the SGSN, the bearer between the SGSN and the RAN comprises: sending, by the SGSN, a request message for a radio access bearer (RAB) assignment to the RAN for the RAN to set up a radio bear with a user equipment (UE), receiving, by the SGSN, a response message for the RAB assignment from the RAN.
 2. A serving general packet radio service support node (SGSN), comprising: a first unit, configured to set up a bearer between the SGSN and a packet data network gateway (PGW) through a serving gateway (SGW) according to first quality of service (QoS) information, wherein the bearer between the SGSN and the PGW is associated with a first bearer ID; and a second unit, configured to set up a bearer between the SGSN and a radio access network (RAN) according to second QoS information which is mapped from the first QoS information according to a mapping relationship between the first Qos information and the second QoS information, wherein the bearer between the SGSN and the RAN is associated with a second bearer ID which is mapped from the first bearer ID according to a mapping relationship between the first bearer ID and the second bearer ID, wherein in a process of setting up the bearer between the SGSN and the RAN, the second unit is configured to send a request message for a radio access bearer (RAB) assignment to the RAN for the RAN to set up a radio bear with a user equipment (UE), and receive a response message for the RAB assignment from the RAN.
 3. A communication network comprising: a serving general packet radio service support node (SGSN) communicatively connected to a packet data network gateway (PGW), a serving gateway (SGW), and a radio access network (RAN), wherein the SGSN is configured to: set up a bearer between the SGSN and the PGW through the SGW according to first quality of service (QoS) information, wherein the bearer between the SGSN and the PGW is associated with a first bearer ID; and set up a bearer between the SGSN and the RAN according to second QoS information which is mapped from the first QoS information according to a mapping relationship between the first Qos information and the second QoS information, wherein the bearer between the SGSN and the RAN is associated with a second bearer ID which is mapped from the first bearer ID according to a mapping relationship between the first bearer ID and the second bearer ID; wherein in a process of setting up a bearer between the SGSN and the RAN, the SGSN is configured to send a request message for a radio access bearer (RAB) assignment to the RAN for the RAN to set up a radio bear with a user equipment (UE), and receive a response message for the RAB assignment from the RAN. 